. >> how mitt romney is pouncing on the comments made by the president's and the new ad by the obama campaign. >> a heart stopping moment for drivers, the close calls when they suddenly find themselves sharing one of >> at 6:30 p.m., a stunning new report changing how scientist of you breast cancer. the discovery may lead to a new way to attack it, more precise treatments and even one day a cure. dr. kim has that story. >> this 36 year-old is at high risk for breast cancer. >> my mother and grandmother are breast cancer survivor, my mom is a two-time breast cancer survivor. >> she does monthly exams but still worries. >> i would love their to be a guarantee that if i find i have it, it would be ok. >> now results of a large study of breast cancer genetics could offer new hope. scientists have identified for genetically distinct types of breast cancer and one of them is much more resemble wing of marion cancer, that suggested is not the organ but the dna that matters. >> it is very exciting. >> this breast cancer surgeon says it is a new way about thinking about cancer and treatment.